diff --git a/lib/filter/src/filter_pkg.vhd b/lib/filter/src/filter_pkg.vhd
index 63ff72c..1359d25 100644
--- a/lib/filter/src/filter_pkg.vhd
+++ b/lib/filter/src/filter_pkg.vhd
@@ -32,7 +32,7 @@ package body filter_pkg is
 	variable res : real_array_t(0 to N-1);
 	variable M : positive;
 	variable phi : real := 0.0;
-	variable dphi : real := 2.0*pi*omega;
+	variable dphi : real := pi*omega;
 	begin
 		if (N mod 2) = 0 then
 			M := N/2;